There are two parts to literate programming. One is the style of commenting and structuring the code, which makes it easy for humans to follow. The other part is the tooling you use when you want to write literate programs, which includes what syntax you use for defining blocks and how do you tangle/weave your code.
There are many tools which support Literate Programming for many different languages. The usual reservation about additional tools applies: each member of a team needs to have it installed, build times get longer, time for a new programmer to start contributing gets longer and so on. It makes many people never even consider LP.
But, it's important to remember, that the tools you use are just an implementation detail. What's important is an idea that source code should be written to be read by humans, not only for computers to execute.
Sometimes there's a need to go over a piece of code with a colleague who doesn't know it. It happens a lot when a new programmer joins a project that has some code written already. This is because to understand the code you need to know the context it was written in. The problem is that programmers often don't document this context enough (or even not at all). This means that reading the code is essentially a reverse engineering someone's thought patterns. It's much more efficient just to sit next to the person and assist him in reading the code by providing a live, context-aware commentary.
LP is "just" that commentary written directly in the code. What's important is that you don't need any special tools to use this style in your comment if your language is flexible enough. Most dynamic languages nowadays are capable of supporting LP style. Don't take my word for it, see for yourself. You can just go and read some LP code. A couple of examples:
http://underscorejs.org/docs/underscore.html
http://coffeescript.org/documentation/docs/grammar.html
http://backbonejs.org/docs/backbone.html
As you can see it's a plain JS (or CS). The pages were created with "docco" tool, but you can read the source with most of the same benefits (excluding rendering of maths symbols, which docco doesn't support anyway).
To sum up: LP is not dead, it just changed its form a little. Many people adopted (or invented independently) this style of code structuring and commenting. Many real-life codebases are written in a literate style because it makes a real difference on how long it will take for someone new to grok the code. Such codebases use docstrings and other mechanisms available in the language to do exactly the same thing that previous LP implementations did.